[libcamera-devel] [PATCH v2 7/8] libcamera: v4l2_device: importBuffers support

[Laurent Pinchart]

Hi Kieran,

Thank you for the patch.

On Wed, Feb 13, 2019 at 03:10:26PM +0000, Kieran Bingham wrote:
> Provide the ability to import a BufferPool into the V4L2Device allowing
> external dmabuf backed buffers to be queued.
> 
> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> ---
>  src/libcamera/include/v4l2_device.h |  1 +
>  src/libcamera/v4l2_device.cpp       | 45 ++++++++++++++++++++++++++++-
>  2 files changed, 45 insertions(+), 1 deletion(-)
> 
> diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h
> index 5a536393a5b5..1d31d1b403bc 100644
> --- a/src/libcamera/include/v4l2_device.h
> +++ b/src/libcamera/include/v4l2_device.h
> @@ -100,6 +100,7 @@ public:
>  	int setFormat(V4L2DeviceFormat *format);
>  
>  	int exportBuffers(BufferPool *pool);
> +	int importBuffers(BufferPool *pool);
>  	int releaseBuffers();
>  
>  	int queueBuffer(Buffer *buffer);
> diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
> index 152bd9930a70..2d0ce7011d8a 100644
> --- a/src/libcamera/v4l2_device.cpp
> +++ b/src/libcamera/v4l2_device.cpp
> @@ -642,6 +642,36 @@ int V4L2Device::createPlane(Buffer *buffer, unsigned int planeIndex,
>  	return 0;
>  }
>  
> +/**
> + * \brief Import the externally allocated \a pool of buffers
> + * \param[in] pool BufferPool of buffers to import
> + * \return 0 on success or a negative error code otherwise
> + */
> +int V4L2Device::importBuffers(BufferPool *pool)
> +{
> +	unsigned int allocatedBuffers;
> +	int ret;
> +
> +	memoryType_ = V4L2_MEMORY_DMABUF;
> +
> +	ret = requestBuffers(pool->count());
> +	if (ret < 0)
> +		return ret;
> +
> +	allocatedBuffers = ret;
> +	if (allocatedBuffers < pool->count()) {
> +		LOG(V4L2, Error)
> +			<< "Not enough buffers provided by V4L2Device";
> +		requestBuffers(0);
> +		return -ENOMEM;
> +	}
> +
> +	LOG(V4L2, Debug) << "Device using an externally provided pool";

Maybe

	"... provided pool of " << pool->count() << " buffers";

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> +	bufferPool_ = pool;
> +
> +	return 0;
> +}
> +
>  /**
>   * \brief Release all internally allocated buffers
>   */
> @@ -682,7 +712,20 @@ int V4L2Device::queueBuffer(Buffer *buffer)
>  	buf.memory = memoryType_;
>  	buf.field = V4L2_FIELD_NONE;
>  
> -	if (V4L2_TYPE_IS_MULTIPLANAR(buf.type)) {
> +	bool multiPlanar = V4L2_TYPE_IS_MULTIPLANAR(buf.type);
> +
> +	if (buf.memory == V4L2_MEMORY_DMABUF) {
> +		if (multiPlanar) {
> +			for (unsigned int p = 0;
> +			     p < buffer->planes().size();
> +			     p++)
> +				planes[p].m.fd = buffer->planes()[p].dmabuf();
> +		} else {
> +			buf.m.fd = buffer->planes()[0].dmabuf();
> +		}
> +	}
> +
> +	if (multiPlanar) {
>  		buf.length = buffer->planes().size();
>  		buf.m.planes = planes;
>  	}

-- 
Regards,

Laurent Pinchart